The overarching goal of this proposal is to address the A2ALL Funding Opportunity Announcement objective to improve understanding of long-term health and well-being of living donors and on the efficacy of living donor liver transplantation (LDLT). Primary aims include: 1) characterizing risks, mediators, moderators, and outcomes that predict the long-term health and patient reported outcomes including well-being of potential living liver donors, and 2) characterizing risks, mediators, moderators, and outcomes that predict long-term outcomes of LDLT recipients and a composite donor-recipient predictive model for long-term outcomes of LDLT. A2ALL studies thus far have clearly demonstrated (LDLT) is a safe and effective alternative to deceased donor liver transplantation (DDLT). More specifically, data from A2ALL have quantified short-term donor morbidity and shown that LDLT recipient short-term morbidity, resource utilization, and other recipient clinical outcomes are comparable to those of DDLT. However, the long-term outcomes of living donation remain undefined, especially the impact of donation on the long-term health and well-being of living donors. Although risk factors that predict outcome are being developed for DDLT using data from national registries, such registries do not currently gather all of the measures needed to develop comprehensive risk predictor models specific to the outcomes of both the living donor and the LDLT recipient. While data on both donor and recipient characteristics have been collected from the current A2ALL cohorts, additional instruments need to be developed that include appropriate measures to fully characterize the risks related to long-term health status and patient reported outcomes including well-being. Finally, there is little knowledge and a lack of standards that focus on the complex healthcare processes involved in transplantation in general, and in LDLT in particular, that mediate and moderate the impact of risk factors on outcomes. Understanding LDLT processes and risk factors is particularly relevant since the enhancement of healthcare processes related to patient safety (e.g., clinician to clinician communication, coordination of care) and to clinician-patient communication (e.g., information exchange, informed consent) have improved health outcomes in other healthcare arenas. Therefore, there is a clear need to expand research on LDLT by exploring the impact of specific risk factors and the effect of healthcare process mediators on outcome domains of long-term health and well-being. PUBLIC HEALTH RELEVANCE: This research will characterize the factors that influence living donors' and living donor recipients' long-term health status and well-being. Specifically, by advancing knowledge of safety, informed consent, and quality of life this proposal will help to expand the pool of living liver donors.